Present postal regulations permit the affixing of a first class letter to a package or envelope containing materials mailed by another postal class. For this reason, publishers and other mass mailing organizations are continually seeking new means for attaching envelopes with first class enclosures to lower class publications. These attachments serve two purposes. They permit the inclusion of first class material for the addressee and provide a means for addressing the host material.
Envelopes have been attached to host publications and the like in the past, but in most instances the methods used have been unreliable or unattractive in concept and execution. For instance, the gumming application of some prior envelopes has either been so extensive that the envelope becomes a permanent part of the host piece, or so minimal that the envelope may be inadvertently separated from the host piece. To overcome these difficulties, extra panels have been added to envelopes for the purpose of attaching the envelopes to host pieces. However, this solution incurs extra costs in material and in production which cannot be justified by the advantages of including the first class material with the lower class material. Meanwhile, shipping labels or envelopes currently used on packages, containers and the like, are not appropriate subsitutes because they do not satisfy the postal regulations covering first class material. Accordingly, the present invention was developed to provide a convenient and economical means for including first class material with lower class material mailed at the lower postal rate.